12.5kw onan air filter service

[Brent Crosser]

I have a 2003 Marquis with a 12.5 Onan generator and the slide only comes out of the front 18 in or so and getting to the air filter does not seem possible. I'm guessing there is a stop to remove and you need something to support it as it looks like it would drop nose down if it slides out any further.  any info on servicing would be greatly appreciated.

Brent Crosser

[Mike Shumack]

Are you unable to remove the access panel?

[Brent Crosser]

i can remove the access panel but the frame rail is across from the air filter and i can barely see it with a mirror. i think the slide has to come out past the frame rail to service.

[Stan Simpson]

Is it possible to get a clear view of the access panel with the slide IN? Dumb question, I know, but just brain-less storming.

[Rayan Poothamby]

Hi Stan,
 I have a 10K Onan and did my air filter couple of week ago. Here are the steps I took:
1)  remove the radiator hose with cap to the side. just remove it from its harness it sits on. No tools required
2) remove three screws from the top of the gen to remove the overflow bottle. Just set it to the side
3) now reach in and flip the two clips holding the air filter cap.
4) pull old filter out and install new.

It took me about 10 mins to do all this. I dont think there is much diffrence between our two gen sets. Hope this helps.

[Brent Crosser]

You have to put the slide out just to get to the access panel. the gen sets between the frame rails and slides out the front but only 18 inches  or so. The air filter is still behind the frame rail and the only way i can even see it it with a mirror. I think the slide has to come out further to service. has anyone serviced a 12.5 on a front slide out?

[Brent Crosser]

Anyone serviced there 12.5 onan in a front slide?

[William Jordan]

For me Not really , just oil and filters which I have had done and done myself since . When I bought the coach 4+ years ago, I asked the tech (BAC) about a full service ( 1000 hours) and was told it was expensive 1000$ plus as they had to pull the generator. Not sure what service that entailed.